100 Camels

Logic
Logic puzzles require you to think. You will have to be logical in your reasoning.

"That Sam is one rich man!" muttered Tom. "As a matter of fact, he owns 100 or more camels."
"Not a chance," replied John, "I know for a fact he owns fewer than 100 camels."
Frank joined in, "Well, he owns at least one camel."

If only one of their statements is true, how many camels does Sam own?

Answer

Sam doesn't own any camels. If the first statement is true then the last is true as well. If the last is true then so is either the first or the second statement. But if the second is true, the first and last aren't necessarily true. Sam can own no camels, making the first and third false, but the second statement true. Since only one can be true, the second is true. He owns zero camels.